As is known, vibration analyzing apparatus utilizes an electromagnetic transducer which transforms the vibrations of a rotating body into an electrical signal having a frequency equal to that of the vibrations, an amplitude proportional to the magnitude of the vibrations, and a phase displacement relative to a reference signal which is related to the location of the point of unbalance on a rotating body. Thus, the transducer transforms the vibrations into an electrical signal equivalent to the vibrations. This signal is then filtered to eliminate all frequencies other than those due to a single rotating part. The resulting vibration signal is then applied to apparatus including an amplitude meter for indicating displacement of the vibrations, a frequency meter for indicating the signal frequency, and a phase determining means such as a phase meter or strobe light.
In the past, a balancing operation required that a trial weight be aded to the rotor and the unbalance determined by vector calculations. Alternatively, plane separators could be used to separate the vibrations in one plane from those in another or the rotor could be vibrated initially with a known force to calibrate the apparatus. These prior art systems, while workable, are cumbersome, complicated and require the use of highly skilled personnel.